Capacitive power transfer with impedance matching network

Abstract

This paper presents the development of a new wireless power transfer technique using capacitive coupling. Capacitive power transfer (CPT) system has been introduced as an attractive alternative to the traditional inductive coupling method. This is due to the CPT benefits of simple topology, fewer components, better EMI performance and robustness to surrounding metallic elements. In this work, a Class-E resonant inverter together with impedance matching network has been utilized as a high frequency ac power source because of its ability to perform the dc-to-ac inversion efficiently. It helps the CPT system to achieve a maximum power transfer. The CPT system is designed and simulated by using Proteus 8 Professional software. The validity of the proposed concept has been verified by conducting a laboratory experimental CPT system. It generates a 9.5W output power through a combined interface (PCB plate) capacitance of 2.82nF, at an operating frequency of 1MHz, with 95.44% efficiency. Also, the proposed CPT system with impedance matching network allow variation to the load while maintaining the efficiency over 80%.